Brazil protests turn violent

A demonstrator with his face covered jumps over a burning barricade in Cinelandia square during a march in support of teachers on strike in Rio de Janeiro, Brazil, Oct. 7, 2013.

Teachers have been on strike demanding better pay for almost two months.

Credit: Felipe Dana/AP

A man wears a mask during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

A demonstrator with his face covered stands next to a burning barricade near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

Demonstrators with their faces covered break ATM machines inside a bank after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Demonstrators with their faces covered take cover behind a sign that reads "Memorias Postumas, Machado de Assis" or "The Posthumous Memoirs-Machado de Assis," near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

Demonstrators with their faces covered try to invade the City Council after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

A demonstrator wears a gas mask over a batman costume during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Firefighters throw water onto a barricade set alight near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

Protesters shout slogans holding banners that reads 'Teachers squad" during a march in support of teachers on strike in Rio de Janeiro, Brazil, Monday, Oct. 7, 2013. Teachers have been on strike demanding better pay for almost two months.

Credit: Felipe Dana/AP

A demonstrator wearing a gas mask runs from tear gas fired by riot police at Cinelandia square during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Riot police officers move toward a bus set on fire by demonstrators near Cinelandia square during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

A woman protects herself from tear gas fired by police near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

Brazilian policemen take position near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

Demonstrators with their faces covered try to enter the City Council during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Brazilian policemen take position near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

A demonstrator with his face covered during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Demonstrators with their faces covered take cover from tear gas fired by riot police outside the City Council after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

People pack Cinelandia square during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Masked protesters set a bus on fire near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Demonstrators with their faces covered take cover from tear gas fired by riot police outside the City Council during a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Felipe Dana/AP

Demonstrators with their faces covered thow stones at riot police near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.

Credit: Silvia Izquierdo/AP

Riot police officers walk past a bus set on fire by masked protesters near Cinelandia square after a march in support of teachers on strike in Rio de Janeiro, Oct. 7, 2013.